Matthew 7:7 Ask and it will be given to you; seek and you will find; knock and the door will be opened to you
Matthew 18:19 Again I say unto you, That if two of you shall agree on earth as touching any thing that they shall ask, it shall be done for them of my Father which is in heaven.
20 For where two or three are gathered together in my name, there am I in the midst of them.
But Jesus did frequently talk about asking him of his Father Lox. Above are just two instances in the same Gospel you quote.
From a Christian perspective, of course, it is fine to ask. That does not mean you will automatically get it nor that God would disfavour others because of it. God will only give what you need. Jesus' was very specific about that.
Likewise, God, through Jesus, asks a lot of things of and from us in return.
Once again it has to be a very individual thing don't you think? Though I do take the point that sometimes by asking to get something others do not have it could be construed as being selfish and asking special favour.
I ask all the time for proof!